X-ray tomographic apparatus has been marketed for many years for the purpose of conducting X-ray cranial tomography to obtain plural, evenly spaced X-ray cuts of cranial sites of interest such as the temporo-mandibular joint for example. In every case tomographic apparatus is positioned such that an X-ray source and an X-ray film cassette are positioned on opposite sides of the patient's anatomical site of interest. The X-ray source and film cassette are movable about the anatomical site of interest while the X-ray source is energized to achieve each tomographic image on the film. Typically the X-ray source and film holder are supported on a movable support that is rotated about a pivot point during film exposure. This pivotal motion blurs out all anatomy in front of and behind the focal point of the X-ray source and thus provides an X-ray exposure that is representative of a cross-section taken through the anatomical area of interest. In many cases, depending upon the character of X-ray tomography that is desired, the apparatus accomplishing rotary movement of the X-ray head and film holder will move either the X-ray head or film holder or both along an elliptical path such as substantially conforming to the configuration of the mandible of the patient. This type of apparatus is widely utilized in dentistry and for maxillo-facial surgery although it has a number of other uses as well. X-ray tomography is especially important in cases where confirmation of precision location is desired for dental implant location in the alveolar arch.